The mission of the Mass Spectrometry Shared Resource (MSSR) is to provide Cancer Therapy & Research Center (CTRC) members and University of Texas Health Science Center (UTHSCSA) investigators with comprehensive, state-of-the-art support for characterization and quantification of proteins, metabolites and other biomedically important molecules using mass spectrometry. The MSSR has been in operation since 1979 and became a Cancer Center Shared Resource in 1998. There are two components of the MSSR, proteomics and metabolomics, which operate at two locations, a 713 sq. ft. space (Proteomics) on the Long (main) campus of the UTHSCSA and a 782 sq. ft. space (Metabolomics) on the Greehey (north) campus of the UTHSCSA in the South Texas Research Facility (STRF). The MSSR is jointly managed by the University and the CTRC. The MSSR services include molecular mass determination, protein identification, protein quantification, sequence characterization of peptides, localization covalent modification, and metabolomics (discovery experiments, targeted quantitative analysis, and small molecule analysis by GC-MS). The shared resource also offers consultations and training to CTRC investigators. The MSSR is directed by Susan Weintraub, Ph.D. The staff of the MSSR includes two-technical Directors, Kevin W. Hakala, M.S, (Proteomics) and Xiaoli Gao, Ph.D., (Metabolomics) with Sam Pardo as the Core Facilities Technologist. The MSSR team has expertise in the use of mass spectrometry to solve important cancer-related questions. During the last award year, the MSSR serviced 14 peer-review funded cancer center members, which comprised 19% of the total core users and contributed to 29 cancer-related peer-reviewed publications during the last funding period. Usage for the first half of 2013 increased two-fold, likely due to the addition of Metabolomics as a service.